<!--
 * @Description: 优先级
 * @Author: charles
 * @Date: 2021-08-11 09:28:40
 * @LastEditors: charles
 * @LastEditTime: 2021-08-11 09:52:03
-->
<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>优先级</title>

  <style>

    ul.menu {
      
    }
    ul.menu > li.menu_item {

    }
    ul.menu > li.menu_item > ul.sub_menu {

    }
    ul.menu > li.menu_item > ul.sub_menu > li {
      color: lightcyan;
      line-height: 2em;
    }
    #introduce {
      color:lightcoral;
      background-color: lightpink;
    }
    .si {
      color: gray !important;
      border: 3px solid #ccc;
    }
  </style>
</head>
<body>
  <div class="tyut">
    <!-- 头部 -->
    <header>
      <div class="first_line"></div>
      <div class="second_line">
        <div class="logo">logo</div>
        <!-- ul 菜单列表 -->
        <ul class="menu">
          <li class="menu_item">
            <span>学校概况</span>
            <ul class="sub_menu">
              <li class="si" style="color: blue;" id="introduce">学校简介</li>
              <li id="history">历史沿革</li>
            </ul>
          </li>
          <li class="menu_item">
            <span>人才培养</span>
            <ul class="sub_menu">
              <li>本科生教育</li>
              <li>研究生教育</li>
            </ul>
          </li>
          <li class="menu_item">
            <span>科学研究</span>
          </li>
        </ul>
      </div>
    </header>
    <!-- /头部 -->
    <!-- 内容 -->
    <!-- /内容 -->
    <!-- 脚部 -->
    <footer>
      <div class="first_line"></div>
      <address>地址</address>
    </footer>
    <!-- /脚部 -->
  </div>

</body>
</html>